Acne is a common inflammatory pilobaceous disease characterized by comedones, papules, pustules, inflamed nodules, superifical pus-filled cysfts, and in extreme cases, sinus formation and deep inflammation, sometimes associated with purulent sacs.
The pathogenesis of acne is complex. An interation between hormones, keratinization, sebum and bacteria somehow determines the course and severity of the disease. Acne begins at puberty when the increase of androgens causes an increase in the size and activity of the pilosebaceous glands. The earliest microscopic change in intrafollicular hyperkeratosis, which leads to restriction of the pilosebaceous follicle with consequent formation of the comedo composed of sebum, keratin, and microorganisms, particularly Propionibacterium (Corynebacterium) acnes. Lipases from P. acnes break down triglycerides in the sebum to form free fatty acids (FFA), which irritate the follicular wall. Retention of sebaceous secretions and dilation of the follicle may lead to cyst formation. Rupture of the follicle with release of the contents into the tissues induces an inflammatory reaction which heals with scarring in severe cases.
Acne tends to appear during puberty and to fade away again, usually spontaneously when growth has stopped. Only rarely does it recede before the age of 20 and occasionally it is still to be found at the age of 30 and beyond. The face is the favorite location affected and in severe cases the alterations cause considerable disfigurement, and make the physical burden of the afflicted person easy to understand.
Acne can be treated by topical application of various lotions, salves and the like or by, for example, localized treatment with, for example, sulphur, resorcinol, salicylic acid, benzoyl peroxide or vitamin A acids.
Salicylic acid is a well recognized anti-acne active ingredient which causes a reduction in intercellular cohesion of the corneocytes (see C. Huber et al, Arch. Derm. Res. 257, 293-297, 1977), thereby dissolving the existing keratin plugs as well as preventing the formation of new ones. In order to best exert its keratolytic and comedolytic effect, the ideal anti-acne composition should deliver and retain optimal concentrations of salicylic acid in the stratum corneum with less penetration through the skin and into the general circulation.
A common method of treating acne is by application of a cleansing pad which contains salicylic acid. However, such pads have proven not totally satisfactory because they have little loft, lack rigidity and are unsatisfactory carriers of the anti-acne salicylic acid active. Also, such pads have unsatisfactory cosmetics which hinder their effectiveness.
In order to improve loft, carded or air-laid fabrics must be used. Such fabrics require a resin be incorporated into the pad; however many resins cause degradation of the salicylic acid active thereby hindering efficacy. Additionally, it has been found that the pads of the present invention deliver high levels of active and provide improved efficacy for, for example, cleansing and oil absorbency.
It is therefore an object of the present invention to provide laminated pads with improved aesthetics and also improved efficacy. Specifially, it is an object of the present invention to provide laminated pads containing two or more nonwoven materials with high degree of loft, greater cleansing capability and oil removal and improved rigidity.